I was looking through byondcore.dll in notepad and found this var, what does it do? Also what does the SHOW_CODE macro, _define, Get, Put and show_banner do?
I'm guessing that world.domain has to do with some old, unused functionality. If you check (or is it checked?) your byond key's hubpage, it would mention that your key is in the dantom domain.

show_banner might have to do with the pager, or the old DS, where there's the advertising-ish banner.
In response to Jon88
Oh yeah, I remember that thing.